During the preparation of the femur during standard cemented hip arthroplasty, the femoral canal is machined or broached to provide an oversized hole for the implant to rest in. This process is accomplished by hand-operated machining or broaching tools. After a bone plug is inserted and the canal cleaned by irrigation, cement is introduced into the canal and the hip stem is pushed into the cement and held in place until the cement mantel hardens. In order to achieve success during the process, the cement must reach and interdigitate with the hard cortical bone to guarantee good cement-bone interface strength. A difficulty arises when the cancellous bone is not sufficiently removed from the canal. Since the cancellous bone is weak, the cancellous bone provides an obstacle in achieving the interface strength. That is, although the cement may penetrate the cancellous bone, the cancellous bone does not provide a strong substrate for attachment to the prosthesis, thereby resulting in failure of the interface between the cement and bone.
Although the machining or broaching is done to remove cancellous bone and to prepare the cortical bone for hip stem implantation, the variations in bone shapes and sizes often require that the surgeon either leave the cancellous bone in place or remove it by curette and other hand techniques. These hand operated techniques are inaccurate, time consuming and rarely remove all of the cancellous bone. Therefore, it is desirable to have an instrument that will automatically remove the cancellous bone accurately and completely.